


So, Rosa is secretly an Avenger

by toastisprettygreat



Series: Avengers x B99 [1]
Category: Brooklyn Nine-Nine (TV), Marvel Cinematic Universe
Genre: Beginning of Season seven of B99, Endgame didn't happen, F/F, F/M, I don't know how to tag this, Jake peralta is a fanboy, M/M, Natasha and Rosa are dating, Steve is the new Captain of the nine nine, after civil war, ok now for serious tags, rosa and natasha are badass girlfriends I don't make the rules, should this be a series?, the avengers meet the nine niner's
Language: English
Status: Completed
Published: 2021-01-18
Updated: 2021-01-18
Packaged: 2021-03-16 17:14:35
Rating: Not Rated
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,162
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/28834713
Author URL: https://archiveofourown.org/users/toastisprettygreat/pseuds/toastisprettygreat
Summary: This is set after Civil War but instead of Endgame Tony and Steve hug it out like bros, and it is at the beginning of season seven of B99 when Captain Holt is demoted.
Relationships: Jake Peralta/Amy Santiago, Kevin Cozner/Ray Holt, Rosa Diaz (Brooklyn Nine-Nine)/Natasha Romanov (Marvel)
Series: Avengers x B99 [1]
Series URL: https://archiveofourown.org/series/2114229
Comments: 2
Kudos: 28





	So, Rosa is secretly an Avenger

**Author's Note:**

> Also if you're seeing this please check out my new Tumblr (not new but I never use it and so far have liked two posts or something like that) toastisprettygreatonao3 . I am going to put updates there and ideas or whatever idk.
> 
> I keep trying to post but the paragraphs are really annoying, I want to have the paragraph things throughout the whole work instead of just at the beginning but they keep merging together so if you know how to fix it please help.

Rosa entered the bullpen and sat down at her desk, the post-it note on her desk reminded her that new captain was meant to be arriving today. She glanced around to see what the other officers thought about a new captain replacing Holt. Jake’s body was radiating anger and Rosa felt bad for him, Captain Holt was the father Jake never had, and he refused to believe there could be another captain which could take his job. 

Terry called a meeting and the group swarmed into the meeting room, the meeting was obviously about the new captain and how everyone had to give them a chance. Jake, obviously, told everyone how he was going to do everything to make them feel the opposite of welcome and Boyle, obviously, agreed. Amy told Jake to at least try and give them a chance because they could be as good Holt, and Hitchcock and Scully said some gross comment about food and if the captain was a girl, which Rosa blocked from her memory. Once Terry declared the meeting over Rosa sprinted back to her desk and sat down to start on paperwork, she didn’t want to be near the two gross men any more than she needed. 

Rosa had barely been at her seat for a half hour when the lift doors opened and everyone looked towards it and gasped, she turned around and smiled at the strange appearance of Captain America in her office space. He smiled his stupidly goofy smile at the detectives standing in front of him in shock, they were all cut out of their trance when Steve was pounced on by an over excited man-child. 

“Omg, you’re Captain America! I’m Jake Peralta, like your number one fan! Omg, this is so cool…I mean, uh, hello Sir, my name is Detective Jake Peralta. It is nice to meet you.” Jake changed his demeanour half way through his introduction and Rosa tried her best not to laugh. She’d met Steve multiple times before and now seeing her friends awed by his presence entertained her, she’d been surprised when she first met him but she was sure she wasn’t like this embarrassing. Although, as she thought back on her first visit to the compound, she’d already been dating her girlfriend at the time and had heard all the embarrassing stories about the avengers. 

She brought herself back into the present to hear Jake bombarding Steve with questions about being an Avenger and saving the world. She took in his overwhelmed expression and he tried to answer the questions and get to the office without being attacked. She stood up and 

"Alright guys, why don't we give Captain America a chance to settle in," she exaggerated the name as Steve looked at her and she smirked slightly before putting her stone cold bitch face on again and continuing, "I'm sure he'll answer all your questions in due course." The detectives and Terry all quieted down before Steve was able to speak to the precinct. 

"Um yes thank you detective. As you may know, I am Steve Rogers, more commonly known as Captain America. I am here to help give back to the community as your new captain, not on avengers work and I hope to make that clear. I know you all miss your precious Captain, Raymond Holt, and I know that means I have large shoes to fill but I hope to do a good job. Detective," Steve looked over at Rosa, "a word in my office please." Steve turned to go into his new office and Rosa went to follow him but before they could reach the office Terry spoke up.  
"I don't mean to be rude Captain, but I am the lieutenant for this precinct. Lieutenant Terry Jeffords." Steve turned and smiled warmly at Terry before shaking his hand.  
"That's great Lieutenant Jeffords, but I want to discuss this precinct with Rosa. Now please, as you were." Steve and Rosa walked into the office, leaving the people in the precinct a chance to gather their thoughts and themselves.

"You called me Rosa." Rosa's voice was stern but Steve knew she was actually concerned about what it meant for their friendship now he was her Captain as well as how it would affect her and Natasha's relationship.  
"I know, I didn't mean to slip up. Anyway, I'll tell them I did research on the precinct, make them seem scared or something. Now, tell me about the team." Rosa smirked, he may not know but he was actually more like Holt than she originally thought.  
"Jake Peralta, big fan of you if you couldn't tell, he wants to help people but is childish at the same time. Does good work though.  
"Charles Boyle, Jake's number one fan and likes to share too many details about his life. Does good work too I guess.  
"Sargent Amy Santiago, Jake's wife and works with the uniforms downstairs. She is way too interested in stationary and other dorky stuff and she wants to become the youngest female captain.  
"Lieutenant Terry Jeffords, loves his three girls and yoghurt. Cracks down and works hard most of the time but can also be fun. Refers to himself in 3rd person.  
"Hitchcock and Scully, gross, very sexual, like to nap a lot. Just stuff like that you know?" Rosa turned to Steve and he nodded as he looked around the room before turning to Rosa.  
"Tell me about Detective Rosa Diaz." Steve smirked and gestured for Rosa to speak. "Come on"  
"Rosa Diaz, will punch a printer if it doesn't work, will punch you if you annoy her too much, oh, and she will proudly fuck your best friend." Rosa smirked as Steve's face blushed at the thought of Rosa and Natasha. "Sorry Cap, I had to. You shouldn't have given me the opportunity." Rose smiled sweetly before walking back to her desk.

"Omg Rosa tell me everything." Jake and Charles approached Rosa before she could take a breath and started asking her all sorts of questions about Steve.  
"Does he smell as good as he looks like he does?" Rosa raised her eyebrows is a mix of disgust and confusion at Charles' question before turning back to Jake.  
"Does he act like he's ancient? Did he ask about me? Does he want to talk to me? Is he going to take us to see the other avengers? Are the other avengers going to come here?" Jakes voice got more and more excited as he asked questions and it took everything in her to not tell him to shut up. Just because she wasn't as excited to meet Steve as he is, doesn't mean she should yell at him. Eventually Jake calmed down enough so Rosa could speak.  
"Steve just wanted to know about you guys and how good a detective you each are. He didn't say anything about the other Avengers, sorry." Rosa looked back down at the paperwork on her desk and was about to start working when a new voice to the precinct from right behind the two men, who hadn't left her alone despite what she said, spoke up.  
"Not even me, aw." Rosa looked up just in time to see the two men from in front of her freak out at the red head.  


"Oh my god how long were you there!?" Jake compiled himself before realising who he was talking to and started fangirling. "Oh my god, you're black widow. Oh my god Charles, Black Widow AND Captain America are in our precinct. Oh my god, I need to go tell Amy. Oh my god." Jake ran off and was soon back with a very confused Amy and Terry.  
The two stared at Natasha who did a small awkward wave before staring at Charles until he walked away, but none of them kept theirs eyes off Rosa and Natasha.  
"So, he didn't mention me at all." Natasha kept a stern gaze on Rosa, the two had complete opposite personalities when they didn't have a crowd, and they weren't going to show that now. Natasha also has no clue what Rosa had told her friends about her relationship status and she didn't want to make her uncomfortable.

"Well, he told me about this person called Nat, but I don't think that's an avenger. I mean, what avenger is called Nat, it's such a stupid name." Rosa smirked at the woman in front of her, she could see out the corner of her eye Jake waving his arms and trying to get her to stop but she ignored him. She liked confusing the others and messing with them, they didn't know much about her life and she liked that. Steve came out of his office and smiled at Nat before offering to let her in, Rosa waves as she walked away. "Bye Romanov, make sure to embarrass him."  


Jake walked over to Rosa as soon as Steve was in his office.  
"Do you ever work?" Rosa looked up at Jake as he sauntered over to her, he ignored her and turned to Charles, Amy and Terry who were listening to their conversation.  


"Captain America called Rosa Rosa before she went into the office, but she never told him her name. She called him Steve, which isn't his name it's actually Captain America. This suggests she knows him from a place where he isn't Captain America. She was mean to Black Widow, which is rude but also suggests she knows her from elsewhere and she called her by her real name surname, which means she's close enough to her to remember that. So, Rosa is secretly an avenger."  


"Wow he's good Diaz, you didn't tell me he was THAT good." Steve stood in the doorway of his office, Natasha next to him. Jake smiles excitedly like a kid.  
"Oh my god! Did I get it right? Is Rosa an avenger?"  
"No." Natasha voice was firm towards Jake but she quickly turned to Rosa and her facial expressions changed, now she was shocked but impressed. "Did you seriously say that to Steve?" Rosas face lit up and she smiled her smug smirk.  
"I had to, he gave me the chance." Both woman giggled for a bit before Natasha looked up at Steve and then across at Rosa.  
"Did he say language?" Steve groaned and Rosa shook her head laughing. "Steve she said a bad language word, why didn't you tell her off?" After a while of Steve constantly sighing and the two girls laughing Terry finally got control of the conversation.  
"Right, everyone listen up!" Terry turned to the uniformed officers who were now focusing on him, "not you guys, the detectives and those two avengers" Once the uniformed officers had their attention back on their work Terry turned to the group who had now collected in front of him, "clearly Diaz knows these two, she is allowed five minutes to explain and for us to get over our shock and then move on." Terry stared at Rosa and she sighed before looking at the two avengers for approval.  
"I'm dating Natasha. You have 4 minutes and 57 seconds for any questions." The two woman looked up at the detectives in front of them with stern looks, which were ultimately terrifying.  
"Where'd you meet?" Amy was the first to speak, and had probably the most normal question out of all of them.  
"Rosa was arresting some guy who had this technology shield was interested in and so a friend of mine at shield sent this team and then they wanted to bring Rosa in to go over stuff and then my friend met Rosa and then she called me later to set us up and then she called Rosa and then-" Terry interrupted Natasha's very detailed story and once they decided that Natasha was taking forever to tell the story to avoid questions they continued with the q&a.  
"Why didn't you tell us Rosa. I thought we were friends, I thought-"  
"I haven't told you guys every time I've gone on a date with someone. And I knew if I told you you'd freak out because Nat's an avenger instead of me dating someone boring."  
"We freak out every time you tell us you date someone." Jake smiled excitedly before Amy told him to calm down. He then hit excited again when he realised something else, "Wait how did you know captain America. Have you been to the avengers secret base?"  
"It's called the compound, and yes, she's been a couple times. Now I don't think this is what you're supposed to do so can you get back to work please. It may be my first day at this precinct but I've been the boss before." Steve gestured for them all to go back to work before pushing Natasha towards the lift, not before she could kiss Rosa goodbye and tell everyone to mind their language.


End file.
